Abstract: A valve has a first duct and a second duct into which the first duct opens at right angles, thereby defining an intersection that forms a seat for a valve disk that slides in the second duct at right angles to the seat between a closed position and an open position. The valve disk has, facing the seat, a deviation surface of curvilinear profile having a narrow base facing toward the seat and widening away from the seat configured to deflect at right angles to the first duct a gaseous stream originating therefrom.

Abstract: A valve has a first duct and a second duct at right angles to the first duct. The first duct opens into a connecting portion of the second duct, defining an intersection that forms a seat for a valve disk that slides in the connecting portion in a direction at right angles to the seat between a closed position and an open position. The connecting portion has two flat walls facing one another and connected by an end wall. The first duct opens onto one of the flat walls. The end wall partially surrounds the valve disk parallel to the a direction of sliding at a distance from an edge of the valve disk that is such that, for the open position, the end wall defines with the edge of the valve disk and the seat a passage.